Battery cell, battery, and electric device

Abstract

The application relates to a battery monomer, a battery and a power utilization device, comprising: an electrode assembly comprising a body and a tab ear led out from an end of the body; a tab connector arranged on one side of the tab ear along a first thickness direction of the tab ear, a welding mark formed on the tab ear and welded with the tab connector; a protective piece arranged on a side of the tab ear away from the tab connector along the first thickness direction, one end of the protective piece extending to a side surface of the body from the tab ear and passing through the body to the end surface of the tab ear, the other end extending to a part of the tab connector arranged protruding from the tab ear; a projection of the protective piece along the first thickness direction covering the welding mark; wherein the protective piece comprises a substrate layer, a buffer layer and a glue layer arranged in sequence, and the protective piece is fixed and bonded with the body and the tab ear through the glue layer.

Description

Technical Field

[0001] This utility model relates to the field of new energy technology, and in particular to a battery cell, a battery, and an electrical device. Background Technology

[0002] With the rapid expansion and development of the new energy market, the market share of new energy vehicles is gradually increasing. As a result, the application of power batteries, the core component of new energy vehicles, is becoming increasingly widespread in people's lives.

[0003] In the power battery industry, the positive and negative tabs of a battery cell are typically made of foil (such as aluminum or copper foil). After the electrode assembly is assembled, protective components (such as protective tape) need to be attached to the tabs during the welding of the tabs and adapter plates to protect them. However, due to limitations of existing equipment, the protective components cannot be perfectly fitted to the tab surface. When the electrode assembly shifts or vibrates in subsequent processes, the protective components will pull on the tabs, leading to tab cracking and severely affecting the yield of the battery cell. Utility Model Content

[0004] Therefore, it is necessary to provide a battery cell, battery, and power device that can reduce the occurrence of tab cracking due to the easy pulling of the protective components.

[0005] On one hand, this application provides a single battery cell, comprising:

[0006] An electrode assembly, including a body and tabs extending from the end of the body;

[0007] An adapter piece is disposed on one side of the electrode along the first thickness direction of the electrode tab, and a solder mark is formed on the electrode tab for welding to the adapter piece;

[0008] A protective element is provided on the side of the electrode tab opposite to the adapter piece along the first thickness direction. One end of the protective element extends from the electrode tab and through the body to the side of the body, and the other end extends from the electrode tab to the portion of the adapter piece that protrudes from the electrode tab. The projection of the protective element along the first thickness direction covers the solder mark.

[0009] The protective component comprises a substrate layer, a buffer layer, and an adhesive layer stacked sequentially, and the protective component is bonded and fixed to the body and the electrode tab by the adhesive layer.

[0010] In one embodiment, the substrate layer and the buffer layer are continuously disposed from one end of the protective member covering the side of the body to the other end of the protective member covering the adapter piece.

[0011] In one embodiment, the thickness of the substrate layer, the buffer layer and the adhesive layer included in the protective member is X1, the thickness of the buffer layer is X2, and X2 / X1 = 0.8-0.95;

[0012] and / or

[0013] The thickness of the substrate layer, the buffer layer and the adhesive layer included in the protective component is X1, the thickness of the buffer layer is X2, and the thickness of the substrate layer is X3, where X1 = 0.5mm-2mm, X2 = 0.5mm-2mm, and X3 = 0.04mm-0.2mm.

[0014] In one embodiment, the thickness of the buffer layer corresponding to the side of the body is less than the thickness of its corresponding other regions.

[0015] In one embodiment, the thickness of the buffer layer corresponding to the side of the body is T1, and the thickness of the buffer layer corresponding to other areas is T2, where T1 = (0.8-0.95)T2;

[0016] and / or

[0017] The buffer layer is a foam buffer layer.

[0018] In one embodiment, the adhesive layer is continuously disposed from one end of the protective member covering the side of the body to the other end of the protective member covering the adapter piece;

[0019] or

[0020] The tab has a connection area located between the solder mark and the end face, and the adhesive layer has a missing area, the missing area at least covering the connection area.

[0021] In one embodiment, the protective member has a first region covering the side of the body, the adhesive layer covering at least a portion of the first region and covering the solder mark, and other regions of the adhesive layer forming the missing region.

[0022] In one embodiment, the projected area of ​​the first region on the side of the body is S1, and the projected area of ​​the adhesive layer on the side of the body is S2, where S2 = (0.5-0.8)S1.

[0023] and / or

[0024] The area of ​​the solder mark is S3, and the projected area of ​​the adhesive layer on the solder mark is S4, where S4 = (1.1-1.5)S3.

[0025] On the other hand, this application also provides a battery, including the aforementioned battery cell.

[0026] Furthermore, this application also provides an electrical device that includes the aforementioned battery cell, or includes the aforementioned battery.

[0027] Compared with the prior art, the above-mentioned battery cells, batteries, and electrical devices have the following advantages:

[0028] 1. The protective component not only covers the electrode tab, but also covers the end face of the electrode tab leading out of the main body and the side of the main body. Furthermore, the adapter piece welded to the electrode tab has a portion protruding from the electrode tab, and the protective component extends from the electrode tab to the protruding portion of the adapter piece. The protective component not only protects the electrode tab but also prevents the electrode tab from being inserted backwards into the main body, thus preventing short circuits. The extension of the protective component to the protruding portion of the adapter piece facilitates its secure fixation.

[0029] 2. In addition to the substrate layer and adhesive layer, the protective component also includes a buffer layer between the adhesive layer and the substrate layer. The buffer layer can expand and contract with the tab bending or vibration, buffering the tensile force on the tab. This improves the tension on the tab caused by the vibration protection component of the electrode assembly during the manufacturing process and actual working conditions, thereby reducing the occurrence of tab cracking and improving the yield of the battery cell. Attached Figure Description

[0030] Figure 1 A cross-sectional view of a battery cell provided in an embodiment of this application;

[0031] Figure 2 A structural diagram of a battery cell provided in another embodiment of this application ( Figure 2 (The tabs of the middle electrode assembly are not bent);

[0032] Figure 3 A structural diagram of a battery cell provided in another embodiment of this application ( Figure 3 (The tabs of the middle electrode assembly are not bent);

[0033] Figure 4 for Figure 3 A cross-sectional view of the protective component of the battery cell shown;

[0034] Figure 5 for Figure 3 A partial enlarged view of the battery cell shown;

[0035] Figure 6 A partially enlarged view of a battery cell provided in another embodiment of this application ( Figure 6 (The tabs of the middle electrode assembly are not bent);

[0036] Figure 7 A partially enlarged view of a battery cell provided in another embodiment of this application ( Figure 7 The tabs of the middle electrode assembly were not bent.

[0037] Explanation of reference numerals in the attached figures:

[0038] 100. Battery cell; 10. Electrode assembly; 11. Body; 111. End face; 112. Side; 12. Tab; 121. Connection area; 20. Adapter piece; 30. Solder mark; 40. Protective component; 41. Substrate layer; 42. Buffer layer; 43. Adhesive layer; 431. Missing area; 50. Housing; 60. Terminal post; Z, First thickness direction. Detailed Implementation

[0039] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a full understanding of this utility model. However, this utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed below.

[0040] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0041] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0042] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0043] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0044] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0045] See Figure 1 and Figure 2 This application provides an electrical device, a battery, and a battery cell 100. The electrical device includes a battery or a battery cell 100 and is capable of providing electrical energy from the battery or battery cell 100. The electrical device can be a vehicle, mobile phone, portable device, laptop computer, ship, spacecraft, electric toy, power tool, energy storage device, amusement equipment, elevator, and lifting equipment, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, or electric airplane toys, etc.; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc.; energy storage devices can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be a carousel, a drop tower, etc.

[0046] The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended vehicles, etc. For new energy vehicles, the aforementioned battery can serve as a driving power source, thereby replacing fossil fuels to provide propulsion. This application does not impose any special restrictions on the aforementioned electrical devices.

[0047] The aforementioned battery can be a battery pack or a battery module. When the battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and multiple battery cells 100. The multiple battery cells 100 can be electrically connected in series, parallel, or a combination of series and parallel connections, and communicate with the battery management system, which controls and monitors the operating status of each battery cell 100. Alternatively, the multiple battery cells 100 can first be combined with a module management system to form a battery module, and then the multiple battery modules can be electrically connected in series, parallel, or a combination of series and parallel connections to form a battery pack together with the battery management system.

[0048] Multiple battery cells 100 can be mounted on supporting structures such as housings, frames, and brackets. The individual battery cells 100 and the battery management system can be electrically connected via electrical connectors, such as busbars. The battery cells 100 can be lithium-ion, sodium-ion, or magnesium-ion batteries, and their external contours can be cylindrical, flat, cuboid, or other shapes, but are not limited to these. Specifically, in this embodiment, the battery cell 100 is a lithium-ion square battery.

[0049] Continue reading Figure 1 In one embodiment of this application, the battery cell 100 includes a housing 50 and an electrode assembly 10. The housing 50 is a hollow structure with an internal cavity for accommodating the electrode assembly 10, electrolyte, and other components. The cavity has an opening through which the electrode assembly 10 is inserted into the housing 50. Since the battery cell 100 in this embodiment is a prismatic battery, the outer contour of the housing 50 is cuboid, and its opening is rectangular. The battery cell 100 also includes a top cover assembly, which is mounted on the housing 50 and covers its opening, thereby creating a relatively closed environment inside the housing 50 to isolate the electrode assembly 10 from the external environment. Since the shape of the top cover assembly needs to match the shape of the opening, the top cover assembly is generally rectangular.

[0050] The electrode assembly 10 is the core component of the battery cell 100. To fit the shape of the housing 50, the electrode assembly 10 in this embodiment is approximately cuboid in shape. The electrode assembly 10 can be arranged in one set or multiple sets side-by-side in the second thickness direction of the housing 50; this is not limited here. Each set of electrode assemblies 10 extends a tab 12 toward the top cover assembly. Specifically, each set of electrode assemblies 10 extends a positive tab and a negative tab toward the top cover assembly.

[0051] For ease of understanding, this article uses one of the tabs 12 as an example. That is to say, the "tab 12" in this article can be either a positive tab or a negative tab, and the "terminal 60" in this article can be either a positive terminal or a negative terminal, as long as the tab 12 connected to the positive terminal is a positive tab and the tab 12 connected to the negative terminal is a negative tab.

[0052] Specifically, see Figure 2 and Figure 3 Each electrode assembly 10 includes a body 11, with tabs 12 extending from the end of the body 11. The battery cell 100 also includes an adapter piece 20, which is disposed on one side of the tab 12 along a first thickness direction Z. A solder mark 30 is formed on the tab 12 for welding to the adapter piece 20. Optionally, the tab 12 and the adapter piece 20 are ultrasonically welded together. The adapter piece 20 can also be welded to a terminal post 60, serving as an intermediate electrical connector between the tab 12 and the terminal post 60 to facilitate electrical connection between the terminal post 60 and the tab 12, thereby extending the tabs 12 of the electrode assembly 10 outside the housing 50. The terminal post 60 serves as the terminal of the electrode assembly 10 and can be connected to the terminals of each battery cell 100 using external electrical connectors to achieve series, parallel, or mixed series and parallel electrical connections between the battery cells 100.

[0053] It should be noted that when the battery cell 100 is a finished product, the tab 12 extending from the end of the body 11 is bent relative to the body 11 to facilitate the electrical connection between the adapter piece 20 and the terminal post 60. At this time, the first thickness direction Z of the tab 12 is perpendicular to the height direction of the housing 50. Figure 1 The first thickness direction Z of the electrode tab 12 is parallel to the second thickness direction of the casing 50. When the battery cell 100 is a semi-finished product, the tab 12 extending from the end of the body 11 has not yet been bent relative to the body 11. At this time, the first thickness direction Z of the tab 12 is parallel to the second thickness direction Z of the casing 50. Figure 1 Parallel in the left and right directions.

[0054] Further reading Figure 3The battery cell 100 also includes a protective element 40, which is disposed on the side of the tab 12 opposite to the adapter piece 20 along the first thickness direction Z. That is, the protective element 40, the tab 12, and the adapter piece 20 are stacked sequentially along the first thickness direction Z of the tab 12. The projection of the protective element 40 along the first thickness direction Z covers the solder mark 30, that is, the protective element 40 forms a first projection on the plane where the tab 12 is located, and the first projection completely covers the solder mark 30. On the one hand, the protective element 40 can prevent burrs from other components from cutting the tab 12, thus providing a certain degree of protection for the tab 12; on the other hand, since the first projection covers the solder mark 30, the protective element 40 can also prevent the solder slag formed during welding from falling onto the surface of other structures (such as the body 11 of the electrode assembly 10) and causing adverse effects.

[0055] Further reading Figure 3 One end of the protective member 40 extends from the tab 12 and through the end face 111 of the tab 12 to the side face 112 of the body 11, while the other end extends from the tab 12 to the portion of the adapter piece 20 that protrudes from the tab 12. Specifically, the side face 112 of the body 11 is generally the larger surface of the body 11. It can be seen that the protective member 40 not only covers the tab 12, but also the end face 111 of the body 11 where the tab 12 is led out, and the side face 112 of the body 11. Furthermore, the adapter piece 20, which is welded to the tab 12, has a portion protruding from the tab 12, and the protective member 40 also extends from the tab 12 to the portion of the adapter piece 20 that protrudes from the tab 12. That is, when the battery cell 100 is a semi-finished product, and the tab 12 leading out from the end of the body 11 has not yet been bent relative to the body 11, the protective member 40 is attached to the electrode assembly 10 and the adapter piece 20 in a Z-shaped manner. On the one hand, the protective component 40 not only protects the tab 12, but also prevents the tab 12 from being inserted backward into the body 11, thus avoiding a short circuit; on the other hand, the protective component 40 extends to the part of the adapter piece 20 that protrudes from the tab 12 and to the side 112 of the body 11, so as to fix the protective component 40.

[0056] Further reading Figure 4 The protective component 40 includes a substrate layer 41, a buffer layer 42, and an adhesive layer 43 stacked sequentially. The protective component 40 is bonded and fixed to the body 11 and the tab 12 via the adhesive layer 43. The substrate layer 41 is the core support layer of the product, providing physical support for the buffer layer 42 and the adhesive layer 43. The adhesive layer 43 is adhesive to facilitate the bonding and fixing of the protective component 40 to the body 11 and the tab 12. The buffer layer 42 can offset impacts and vibrations through its elastic deformation and energy absorption characteristics.

[0057] The buffer layer 42 is made of a material with good cushioning performance, such as a foam buffer layer or a rubber buffer layer. The adhesive layer 43 is made of a material with good adhesion to ensure the bonding and fixing effect between the protective component 40 and the body 11 and the tab 12.

[0058] As described in the background section, due to limitations of existing equipment, the protective component 40 cannot achieve complete adhesion to the surface of the tab 12. When the electrode assembly 10 shifts or vibrates in subsequent processes, the protective component 40 will pull on the tab 12, leading to cracking and severely impacting the yield of the battery cell 100. The battery cell 100 provided in this application includes a buffer layer 42 located between the adhesive layer 43 and the substrate layer 41, in addition to the substrate layer 41 and adhesive layer 43. The buffer layer 42 can expand and contract with the tab 12 as it bends or vibrates, buffering the tensile force on the tab 12. This improves the protection against the tab 12 during manufacturing and actual operating conditions, thereby reducing the occurrence of tab 12 cracking and improving the yield of the battery cell 100.

[0059] See Figure 5 The substrate layer 41 and the buffer layer 42 are continuously provided from one end of the protective member 40 covering the side 112 of the body 11 to the other end of the protective member 40 covering the adapter piece 20. That is, the protective member 40 has a substrate layer 41 and a buffer layer 42 at each location to further ensure the buffering effect of the protective member 40.

[0060] In some embodiments, see further reference. Figure 5 The adhesive layer 43 is continuously provided from one end of the protective member 40 covering the side 112 of the body 11 to the other end of the protective member 40 covering the adapter piece 20. That is, the adhesive layer 43 is provided at all points of the protective member 40 to ensure the bonding and fixing effect between the protective member 40 and the body 11 and the tab 12.

[0061] Optionally, continue reading Figure 4 The sum of the thicknesses of the substrate layer 41, buffer layer 42, and adhesive layer 43 included in the protective component 40 is X1, that is, the total thickness of the protective component 40 is X1, and the thickness of the buffer layer 42 is X2. X2 / X1 = 0.8-0.95.

[0062] When the buffer layer 42 of the protective component 40 is too thin, the buffering effect is limited. After the tab 12 is bent, the protective component 40 is located between the tab 12 and the body 11, and after the core is closed, the protective component is located between the two sets of electrode assemblies 10 of 40. If the buffer layer 42 is too thick, it will affect the space utilization. By setting X2 / X1 = 0.8-0.95, the thickness of the buffer layer 42 is neither too thin nor too thick, which can improve the space utilization while ensuring the buffering effect.

[0063] In some specific implementations, X2 / X1 is 0.8, 0.85, 0.9, or 0.95, etc. The specific value of X2 / X1 is not limited and can be selected as needed.

[0064] The thickness of the substrate layer 41 is X3, where X1 = 0.5mm-2mm, X2 = 0.5mm-2mm, and X3 = 0.04mm-0.2mm. This arrangement ensures that the total thickness of the protective component 40, the substrate layer 41, the buffer layer 42, and the adhesive layer 43 are all within a suitable range, thus improving space utilization while guaranteeing buffering and bonding effects.

[0065] It should be noted that the total thickness of the protective element 40, or the thickness of the substrate layer 41, buffer layer 42, and adhesive layer 43, are dimensions of the protective element 40 in a direction perpendicular to its plane.

[0066] It is conceivable that in other embodiments, the specific values ​​of the total thickness of the protective element 40 and the thicknesses of the buffer layer 42, the substrate layer 41 and the adhesive layer 43 are not limited, and can be selected as needed.

[0067] Furthermore, the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 is less than the thickness of its corresponding other areas. That is, the protective member 40 has a first area covering the side 112 of the body 11, and the other areas of the protective member 40 are second areas, with the thickness of the buffer layer 42 corresponding to the first area being less than the thickness of the second area. When the battery cell 100 is assembled, the two sets of electrode assemblies 10 are arranged side by side in the second thickness direction of the housing 50, at which time the protective member 40 is located between the bodies 11 of the two sets of electrode assemblies 10 in the second thickness direction. When the buffer layer 42 is too thick, it will result in a large gap between the two sets of electrode assemblies 10, which will affect the insertion of the electrode assembly 10 into the housing or affect the overall flatness of the electrode assembly 10. By setting the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 to be less than the thickness of its corresponding other areas, the gap between the two sets of electrode assemblies 10 can be reduced, which facilitates the insertion of the electrode assembly 10 into the housing and helps to ensure the overall flatness of the electrode assembly 10. Furthermore, the buffer layer 42 in other areas is thicker, which can ensure the buffering effect in other areas, reduce the occurrence of tab 12 cracking, and improve the yield of battery cell 100.

[0068] The thickness of the buffer layer 42 corresponding to the side 112 of the body 11 is T1, and the thickness of the buffer layer 42 corresponding to other areas is T2, where T1 = (0.8-0.95)T2. When the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 is small, its buffering effect is limited. When the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 is large, it will result in an excessively large gap between the two sets of electrode assemblies 10. By setting T1 = (0.8-0.95)T2, the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 can be kept within a suitable range, ensuring the buffering effect of this part while avoiding an excessively large gap between the two sets of electrode assemblies 10.

[0069] It should be noted that although the relationship between T1 and T2 is defined here, the values ​​of T1 and T2 still meet the design requirement of X2 / X1 = 0.8-0.95. That is, although the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 and the thickness corresponding to other areas are designed differently, the thickness of the buffer layer 42 corresponding to the side 112 of the body 11 and the thickness corresponding to other areas still meet the design requirement of X2 / X1 = 0.8-0.95.

[0070] In other embodiments, see Figure 6 The tab 12 has a connection area 121 located between the solder mark 30 and the end face 111, and the adhesive layer 43 has a missing area 431, which at least covers the connection area 121. After the battery cell 100 is assembled, the connection area 121 of the tab 12 will be bent, so the risk of the connection area 121 tearing is relatively high. Since the missing area 431 of the adhesive layer 43 at least covers the connection area 121, that is, the adhesive layer 43 is segmented in this embodiment, and the adhesive layer 43 on the connection area 121 is removed. Removing the adhesive layer 43 on the connection area 121 can prevent the adhesive layer 43 from pulling the connection area 121 when the tab 12 is bent or vibrated, thereby preventing the tab 12 from tearing, and thus further reducing the risk of the tab 12 tearing.

[0071] In some other embodiments, see [reference] Figure 7The protective component 40 has a first area covering the side surface 112 of the body 11. The adhesive layer 43 covers at least a portion of the first area and the solder mark 30 on the tab 12. Other areas of the adhesive layer 43 form missing areas 431. That is, in this embodiment, the adhesive layer 43 is also segmented. The protective component 40 only has the adhesive layer 43 in a portion of the side surface 112 of the body 11 and at the position corresponding to the solder mark 30. There is no adhesive layer 43 in the remaining positions. The areas with the adhesive layer 43 are bonded to the body 11 and the tab 12 to ensure the fixing effect between the protective component 40 and the electrode assembly 10. The areas without the adhesive layer 43 only have the substrate layer 41 and the buffer layer 42, which have no bonding function and cannot be directly pasted onto the tab 12 or the body 11. This can reduce the pulling between the protective component 40 and the tab 12, thereby further reducing the risk of the tab 12 tearing.

[0072] It should be noted that an adhesive layer 43 is provided at the location of the solder mark 30. The adhesive layer 43 can adhere to the solder slag and prevent short circuits caused by solder slag splashing in the solder mark area. Specifically, the area of ​​the adhesive layer 43 is larger than the area of ​​the solder mark 30 to ensure that the entire solder mark area is covered by the adhesive layer 43, resulting in better protection.

[0073] In some specific embodiments, the projected area of ​​the first region on the side 112 of the body 11 is S1, and the projected area of ​​the adhesive layer 43 on the side 112 of the body 11 is S2, where S2 = (0.5-0.8)S1. If the area of ​​the adhesive layer 43 in this region is too large, it is easy to stick to the bending area (connection area 121) of the tab 12, increasing the risk of the tab 12 tearing. If it is too small, the bonding reliability is reduced, and the protective member 40 is easy to fall off from the side 112 of the body 11 when the electrode assembly 10 vibrates. By setting S2 = (0.5-0.8)S1, the risk of the tab 12 tearing can be reduced while ensuring the bonding effect between the protective member 40 and the body 11, reducing the detachment of the protective member 40.

[0074] Optionally, S2 / S1 can be selected as 0.5, 0.6, 0.7 or 0.8, etc. The specific value of S2 / S1 is not limited and can be selected according to the needs.

[0075] Furthermore, the area of ​​the solder mark 30 is S3, and the projected area of ​​the adhesive layer 43 on the solder mark 30 is S4, where S4 = (1.1-1.5)S3. If the area of ​​the adhesive layer 43 corresponding to the solder mark area is too large, it is easy to stick to the connection area 121 of the tab 12, increasing the risk of tearing of the tab 12. If the area of ​​the adhesive layer 43 corresponding to the solder mark area is too small, it will affect the adhesion effect of foreign objects in the solder mark area. By setting S4 = (1.1-1.5)S3, the risk of tearing of the tab 12 can be reduced while ensuring the adhesion effect of the adhesive layer 43 to foreign objects in the solder mark area.

[0076] Optionally, S4 / S3 can be selected as 1.1, 1.2, 1.3, 1.4 or 1.5, etc. The specific value of S4 / S3 is not limited and can be selected according to the needs.

[0077] It should be noted that when the adhesive layer 43 is segmented, the thickness settings of the substrate layer 41, buffer layer 42 and adhesive layer 43 can refer to the case where the adhesive layer 43 is continuously set, and will not be elaborated here.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A battery cell, characterized in that, include: The electrode assembly (10) includes a body (11) and a tab (12) extending from the end of the body (11); The adapter piece (20) is disposed on one side of the electrode (12) along the first thickness direction (Z), and a solder mark (30) is formed on the electrode (12) to be welded to the adapter piece (20); A protective element (40) is provided on the side of the tab (12) facing away from the adapter piece (20) along the first thickness direction (Z). One end of the protective element (40) extends from the tab (12) through the body (11) to the side surface (112) of the tab (12), and the other end extends from the tab (12) to the portion of the adapter piece (20) protruding from the tab (12). The projection of the protective element (40) along the first thickness direction (Z) covers the solder mark (30). The protective component (40) includes a substrate layer (41), a buffer layer (42) and an adhesive layer (43) stacked in sequence. The protective component (40) is bonded and fixed to the body (11) and the tab (12) through the adhesive layer (43).

2. The battery cell according to claim 1, characterized in that, The substrate layer (41) and the buffer layer (42) are continuously disposed from one end of the protective member (40) covering the side (112) of the body (11) to the other end of the protective member (40) covering the adapter piece (20).

3. The battery cell according to claim 1, characterized in that, The thickness of the substrate layer (41), the buffer layer (42) and the adhesive layer (43) included in the protective component (40) is X1, the thickness of the buffer layer (42) is X2, and X2 / X1 = 0.8-0.95; and / or The thickness of the substrate layer (41), the buffer layer (42) and the adhesive layer (43) included in the protective component (40) is X1, the thickness of the buffer layer (42) is X2, and the thickness of the substrate layer (41) is X3, where X1 = 0.5mm-2mm, X2 = 0.5mm-2mm, and X3 = 0.04mm-0.2mm.

4. The battery cell according to claim 1, characterized in that, The thickness of the buffer layer (42) corresponding to the side (112) of the body (11) is less than the thickness of its corresponding other regions.

5. The battery cell according to claim 4, characterized in that, The thickness of the buffer layer (42) corresponding to the side (112) of the body (11) is T1, and the thickness of the buffer layer (42) corresponding to other areas is T2, T1 = (0.8-0.95)T2; and / or The buffer layer (42) is a foam buffer layer (42).

6. The battery cell according to claim 1, characterized in that, The adhesive layer (43) is continuously provided from one end of the protective member (40) covering the side (112) of the body (11) to the other end of the protective member (40) covering the adapter piece (20); or The tab (12) has a connection area (121) located between the solder mark (30) and the end face (111), and the adhesive layer (43) has a missing area (431) that at least covers the connection area (121).

7. The battery cell according to claim 6, characterized in that, The protective element (40) has a first region covering the side (112) of the body (11), the adhesive layer (43) covers at least a portion of the first region and covers the solder mark (30), and the other regions of the adhesive layer (43) form the missing region (431).

8. The battery cell according to claim 7, characterized in that, The first region has a projected area of ​​S1 on the side (112) of the body (11), and the adhesive layer (43) has a projected area of ​​S2 on the side (112) of the body (11), where S2 = (0.5-0.8)S1. and / or The area of ​​the solder mark (30) is S3, and the projected area of ​​the adhesive layer (43) on the solder mark (30) is S4, where S4 = (1.1-1.5)S3.

9. A battery, characterized in that, Includes the battery cell as described in any one of claims 1-8.

10. An electrical appliance, characterized in that, It includes the battery cell as described in any one of claims 1-8, or the battery as described in claim 9.

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